A coupling device is used, in particular, in the field of aeronautics, especially in order to equip nacelles.
A nacelle is a fairing element making it possible to protect a jet engine of an aircraft. A nacelle comprises, in general, a front air inlet section, a middle section intended for surrounding a blower of the turbojet engine, and a rear section formed from at least one first and one second half-shell which are mounted movably in rotation on a mast so as each to be capable of being deployed between an operating position and a maintenance position.
Locking devices are arranged in the region of junction zones between the two articulated elements, said junction zones being arranged in the lower part, that is to say at 6 o'clock, and in the upper part, that is to say at 12 o'clock, in order to prevent the nacelle from opening during flight.
In the upper part of the nacelle, the mast is arranged between the two half-shells so that it is sometimes necessary to provide a coupling device making it possible to connect the two half-shells in spite of their spacing. In general terms, the coupling elements make it possible to transfer tensile forces from one half-shell to another, the transfer of compressive forces being ensured by means of dedicated compression rods called “bumper rods”.
Thus, a conventional coupling device comprises a rod connected to the first and to the second half-shell respectively in the region of a first end and of a second end, at least one of the ends of the rod comprising a head intended for cooperating with locking means of the corresponding half-shell, so as to effect the removable fastening of the rod to the corresponding movable element.
It is then possible to separate the rod from at least one of the two half-shells in order to make it possible to space these apart during maintenance operations.
This type of coupling device has the disadvantages set out below.
Once the rod is detached from the corresponding half-shell, the latter falls under the effect of gravity.
A repositioning ramp system is generally provided, in order to allow the re-engagement of said rod with respect to the corresponding half-shell during the closing of the nacelle, so that the head of the rod cooperates with the locking means. The repositioning ramp system is installed, in particular, in the region of the jet engine.
A system of this type does not make it possible to ensure the repositioning of the rod in a reliable way. Moreover, it presents problems of bulk and of interface management between the nacelle itself and the jet engine. Another disadvantage is due to the introduction of interfering forces arising from the vibration or thermal expansion attributable to the jet engine.